Often it may be sufficient to compute the spin-orbit matrix
elements in a smaller basis or at a lower computational level than the energies. It is
therefore possible to replace the energy eigenvalues
by precomputed values, which are passed to the spin-orbit program by the MOLPRO
variable HLSDIAG. The energy values in HLSDIAG must be in exactly the same order
as the states in the records given on the HLSMAT card. Before any spin-orbit calculation,
the variable HLSDIAG must either be undefined or cleared (then the original energies are used),
or must contain exactly the number of energies as the number of states treated in the
subsequent spin-orbit calculation (use CLEAR,HLSDIAG to clear any previous values
in the variable). It is the user's responsibility that the order of the energies in
HLSDIAG is correct!